It would be good not to have the flickr id number, but not sure how downloadair would handle repeated back-ups of the same photos.
For example, I have over 1,000 flickr photos & videos spread across several albums, which I regularly back up to a USB HD. When I run downloadair, it adds the new flickr photos and overwrites the existing ones, BUT if the existing photos had been renamed in an earlier session, I could end up with multiple copies of the same photo.